Here's an example of a boosted post from Bustle, who promoted one of its articles on Facebook. Paying to "boost" a post you already posted organically to your Facebook Business Page can greatly benefit content that has mass appeal -- versus a post that targets a specific segment of your audience. Bustle's choice of boosted post here falls into that first category.
It's visual. The picture alone is worth a thousand words about how much fun this concert would be. Not only is it on the beach, it was also taken on a gorgeous day and the stage looks amazing. Also, it clearly represents what to expect during the event, and it catches the eye as someone scrolls through their News Feed. (The beautiful ocean water definitely helps.) Facebook Marketing For Individuals - How to succeed With Facebook Marketing